Question

Out of the given equations, is not a quadratic equation.

• A. $x^2-2=0$
• B. ${(x+2)}^2=x^2$
• C. $x^2-5x=-6$
• D. $5t^2-\sqrt{3}t+7=\sqrt{5}$

Answer 1

The correct option is B ${(x+2)}^2=x^2$

$A\mathrm{quadratic}\mathrm{equation}\mathrm{is}\mathrm{of}\mathrm{form}{\mathrm{ax}}^2+\mathrm{bx}+c=0,\mathrm{where}a\ne 0.\mathrm{when}\mathrm{we}\mathrm{simplify}\mathrm{the}\mathrm{equation}{(x+2)}^2=x^2,\mathrm{it}\mathrm{will}\mathrm{become}4x+4=0,\mathrm{which}\mathrm{is}\mathrm{not}a\mathrm{quadratic}\mathrm{equation}.$